1. Field of the Invention
The invention is directed to forming a seamable belt for a paper making machine and, in particular, a seamable belt base for a paper making machine.
2. Discussion of Background Information
It is known from International Publication No. WO 89/12717 that a seam capable base for a press fabric can be created by “folding” a tube of woven fabric and removing cross-direction (CD) yarns at the folds on each end. In this way, machine direction (MD) yarns at these ends or folds can then function as the seam loops. The ends or seam loops of the base can be aligned and connected with a pintle to form an endless base for the belt. The base can be needled and finished in any conventional matter in order to form a normal press seam fabric.
In other methods, it is known that the above-noted tube of fabric can be constructed with a spiraled “multiaxial” method. However, to use endless woven or spiraled tubes in the above-noted manner, the tubes have to be produced to length based on the order. Further, as these tubes are generally only about 1-1.5 m wide, a number of these folded tubes must be combined with MD joins in order to achieve a width of 10-12 m, which is generally utilized in paper making machines. The ends of these tubes can be joined together by forming MD yarn loops by removing CD yarns.
Further, as an array of parallel yarns “reinforced” with needled batt, resins, or other nonwovens can be utilized in forming the described tube for the base, a strong single layer top ply fabric can be provided over the joined area, or needled batt, added resin, thermoplastic “welding”, etc. to keep the join in the two fabric ends intact for processing. Still further, a knit fabric can be used where the loops are provided as a spiral link.
In a further alternative, it is known to position a membrane “insert” within the tube, e.g., prior to folding.